Systems and methods for solar energy storage, transportation, and conversion utilizing photochemically active organometallic isomeric compounds and solid-state catalysts

Abstract

A system for converting solar energy to chemical energy, and, subsequently, to thermal energy includes a light-harvesting station, a storage station, and a thermal energy release station. The system may include additional stations for converting the released thermal energy to other energy forms, e.g., to electrical energy and mechanical work. At the light-harvesting station, a photochemically active first organometallic compound, e.g., a fulvalenyl diruthenium complex, is exposed to light and is photochemically converted to a second, higher-energy organometallic compound, which is then transported to a storage station. At the storage station, the high-energy organometallic compound is stored for a desired time and/or is transported to a desired location for thermal energy release. At the thermal energy release station, the high-energy organometallic compound is catalytically converted back to the photochemically active organometallic compound by an exothermic process, while the released thermal energy is captured for subsequent use.

What is claimed is: 
     
       1. A system for converting light energy to thermal, mechanical or electrical energy, the system comprising:
 (a) a light-harvesting station containing a photochemically active organometallic compound, wherein the photochemically active organometallic compound is converted to a higher-energy organometallic compound upon exposure to light, wherein the photochemically active organometallic compound is a fulvalenyl diruthenium compound selected from the group consisting of the following compounds: 
 
       
         
           
           
               
               
           
         
         (b) a storage station containing the higher-energy organometallic compound, wherein the higher-energy organometallic compound does not spontaneously convert to lower-energy compounds, but is capable of being converted to the lower-energy photochemically active organometallic compound upon exposure to a solid-state catalyst; and 
         (c) a thermal energy release station containing the solid-state catalyst capable of catalyzing the catalytic conversion of the higher-energy organometallic compound to the lower-energy photochemically active organometallic compound at ambient temperatures without the need to heat the higher-energy organometallic compound, wherein the conversion of the higher-energy organometallic compound to the photochemically active organometallic compound releases at least about 15 kcal/mol of thermal energy. 
       
     
     
       2. The system of  claim 1 , wherein the system converts solar energy to thermal energy. 
     
     
       3. The system of  claim 2  further comprising a station for converting thermal energy to electrical energy. 
     
     
       4. The system of  claim 1 , wherein the conversion of the higher-energy organometallic compound to the photochemically active organometallic compound releases at least about 30 kcal/mol of thermal energy. 
     
     
       5. The system of  claim 1 , wherein the lower-energy photochemically active organometallic compound and the higher-energy organometallic compound are capable of being interconverted without substantial degradation for at least 10 cycles. 
     
     
       6. The system of  claim 1 , wherein the light-harvesting station comprises a container housing the photochemically active organometallic compound during its conversion to the higher-energy organometallic compound, wherein the container is configured for exposing the photochemically active organometallic compound to sunlight. 
     
     
       7. The system of  claim 6 , wherein the container is adapted for exposing a continuously flowing liquid to sunlight. 
     
     
       8. The system of  claim 1 , wherein the storage station comprises a storage container configured for storing the higher-energy organometallic compound. 
     
     
       9. The system of  claim 8 , wherein the storage container is transportable. 
     
     
       10. The system of  claim 8 , wherein the storage container comprises a pipeline adapted for transporting a continuously flowing liquid from the light-harvesting station to the thermal energy release station. 
     
     
       11. The system of  claim 1 , wherein the thermal energy release station comprises a heat exchange fluid for transferring the thermal energy generated by the catalytic conversion to serve a desired purpose. 
     
     
       12. The system of  claim 1 , wherein the thermal energy release station comprises a thermoelectric material for direct conversion of heat to electrical energy. 
     
     
       13. The system of  claim 1 , wherein the thermal energy release station comprises a heat exchanger, said heat exchanger housing the solid state catalyst such that the solid state catalyst can efficiently contact the photo chemically active organometallic compound, and accomplish the catalytic conversion to the lower-energy compound. 
     
     
       14. The system of  claim 1 , wherein the catalytic conversion is capable of occurring at a temperature of less than about 60° C. 
     
     
       15. The system of  claim 1 , wherein the solid-state catalyst is selected from the group consisting of charcoal, alumina, and a solid comprising coordinating groups. 
     
     
       16. The system of  claim 1 , wherein the solid-state catalyst is charcoal. 
     
     
       17. The system of  claim 1 , wherein the system is configured for providing the higher-energy organometallic compound to the thermal energy release station in solution. 
     
     
       18. The system of  claim 17 , wherein the system is configured for continuously flowing a solution of the higher-energy organometallic compound through the thermal energy release station. 
     
     
       19. The system of  claim 18 , wherein the solid-state catalyst is packed or fixedly supported in the thermal energy release station such that the flow of the solution of the higher-energy organometallic compound does not remove the catalyst from the thermal energy release station. 
     
     
       20. The system of  claim 1 , wherein the system is configured for providing the higher-energy organometallic compound to the thermal energy release station in solid state. 
     
     
       21. The system of  claim 1  further comprising a pipeline adapted for returning a solution from the thermal energy release station to the light-harvesting station.